What evidence supports the theory of endosymbiosis ? Mitochondria and chloroplasts are similar to prokaryotes they do not have theh own membranes Eukaryotic cells contain mitochondria and some contain chiorophyll. contain ribosomes. Mitochondrial DNA is most closely related to a parasitic bacteria called Rickettsia prowazekit, causes epidemic typhus. Both mitochondria and chloroplasts have a circular DNA genome, like a bacteria's genome, but smaller. This DNA is passed from a mitochondrion to its offspring and separate from the host" cell's genome in the nucleus. Both mitochondria and chloroplasts have their own ribosomes to produce proteins. Eukaryotic cells were on earth before prokaryotic ones.